Jordan plug and method of making the same



Aug. 14, 1956 B. E. PREVOST ETAL 2,758,516

JORDAN PLUG AND METHOD OF MAKING THE SAME Filed May 17, 1954 2 Sheets-Sheet l 3 25 25 2 INVENTOR.

38 BR mm 11 PREVOST 20 BYMYRON a. SMITH Fig. 6: A Egan/2am *TPA lm ATTORNEYS Aug. 14, 1956 E. E4 PREVOST ETAL JORDAN PLUG AND METHOD OF MAKING THE SAME Filed May 17, 1954' 2 Sheets-Sheet 2 AL/ g /77 4/ HHHH IIIJHIHHH INVENTOR. BRUNO E PREVOS T BY M YRON 6. SMI

ATTORNEY 2,758,516 Patented Aug. 14, 1956 ice JORDAN PLUG AND METHOD or MAKING THE SAME Bruno E. Prevost, West Boxford, Mass, and Myron G. 'Smith, Salem, N. H, assignors to John W. Bolton & Sons, Inc., Lawrence, Mass, a corporation of Massachusetts Application May 17, 1954, Serial No. 430,056

9 Claims. (Cl. 92-27) This invention relates to the frustro conical plugs of Jordan engines and especially to such plugs having bars or knives angularly oflfset from the longitudinal centre line thereof.

In a somewhat related art, cylindrical rotors having angularly offset spiraled bars have been proposed as in U. S. Patent No. 63,832 to Beach issued April 16, 1867 and U. S. Patent No. 484,056 to Simonet issued October 11, 1892. Such rotors have been used in pairs for grinding pulp therebetween and the bars have been integral with the rotor body as well as being helically spiraled thereby presenting diificulties in manufacture and replacement. It has also been proposed to provide a frustro conical rotor with angularly olfset spiraled bars as in U. S. Patent No. 27,246 to Sweet issued February 21, 1860 and U. S. Patent No. 1,467,207 to Strattman issued September 4, 1923.

The bars of this application however, are not integral with the plug body and are not spiralled around the plug body as in the above mentioned patents.

The bars or knives of this invention are carried by a frustro conical plug and they are straight rather than spiraled but angularly offset from the longitudinal centre line of the plug. They are demountably fixed in straight undercut grooves and are not parallel to each other since they are spaced apart more closely at the small end of the plug than at the large end of the plug.

A plurality of groups of angularly olfset straight bars have been provided on frustro conical rotors by previous patentees as in U. S. Patent No. 282,098 to Manning issued July 31, 1883 or U. S. Patent No. 1,184,058 to Watson issued May 23, 1916. While the bars of these patents are straight they are not angularly displaced at the same angle to each other as in this invention. Instead the four or five bars of each group are parallel to each other and'of dilferent lengths but the bars of the various groups are angularly displaced from those of other groups.

Frustro conical rotors having straight bars either integral therewith or demountably carried in grooves therein have also been proposed as in U. S. Patent No. 794,187 to Pfeifer issued July 11, 1905 and U. S. Patent No. 1,633,308 to Bolton issued June 21, 1927. The bars of the Bolton patent may have straight side faces extending longitudinally thereof or may be spiralled and they are carried in grooves whereby they are demountable. The bottom wall of the grooves and the bottom faces of the bars or knives in the Bolton patent, however, are curved in order to make each groove of uniform depth through its length while also being angularly oifset on the curved surface of the frustro conical plug. The making of a groove of, uniform depth in a conical surface, when the groove is angularly offset from the cone axis is difficult and the curving of the bottom face of a bar to conform to the groove is also diflicult, time consuming and costly.

So far as I am aware, no one has previously achieved an undercut slotted plug having angularly olfset bars whereby the bars and separatorsmay be assembled and disassembled by an endwise sliding movement.

It is the principal objectof this invention to provide or grooves into which the a new Jordan plug having angularly offset straight plug bars which bars provide desirable pumping action and are especially firmly held in the plug grooves for the full length of the plug.

Another object of the invention is to provide a Jordan plug with angularly offset bars which can be made with,

considerable saving in manufacturing cost over previous similar plugs and yet will provide longer wear.

A further object of the invention is to provide a new process .of making slotted Jordan plugs with straight angularly offset bars which process eliminates steps formerly used and requiring. special costly machinery.

Still another object of the invention is to secure the advantages of angularly oflset bars on a Jordan plug while detachably mounting the bars in undercut slots bars may be slid from one end of the plug.

A still further object of the invention is to provide a Jordan plug with undercut bar slots, straight bars axially insertable in the slots, straight separators axially insertable between the bars and yet with all of the bars angularly offset a like amount.

Other objects and advantages of the invention will be apparent from the following description of the drawings and from the drawings wherein Fig. 1 is a diagrammatic plan view of a frustro conical Jordan plug showing an angularly disposed groove being formed therein according to this invention.

Fig. 2 is an elevation from the small end of the plug of Fig. l'showing the step of positioning the plug for .the milling of an angularly disposed groove of non uniform depth.

Fig. 3 is a diagrammatic side elevation of the plug shown in Figs. 1 and 2.

Fig. 4 is an elevation from the large end of the plug showing the plug after the step of cutting angularly disposed grooves of non-uniform depth therearound has been completed, and during the step of removing the curved surface between the grooves to accommodate ordinary separators.

Fig. 5 -is a side elevation of a plug according to this invention after the step of slideably inserting the bars or knives in the angularly offset grooves has been completed.

Fig. 6 is a fragmentary elevation fromv the large end of the plug showing the step of inserting separators between the bars, by endwise sliding of the same.

Fig. 7 is a fragmentary side view of a typical Jordan grinding device with parts broken away, showing the step of grinding or otherwise removing the upper edge portion of the plug bars into conformance with the curved inner surface of a Jordan shell.

Fig. 8 is an enlarged diagrammatic view from the large end of the plug showing the depth of the side walls of a groove as greater in the central portion than at either opposite end thereof.

Figs. 9, 10 and 11 are plan, side and end views of a typical plug bar or knife according to the invention.

In the drawings a frustro having a large end 20, an intermediate portion 2.1 and a small end 22. The body A may be of any well known type so long as there is sufiicient material entirely along, or at spaced portions along the curved surface 23 thereof to permit the cutting of undercut grooves therein for receiving and retaining a plurality of longitudinally extendinng, spaced, plug bars or knives. While such plugs are usually called slotted plugs, the term groove is used herein since the term slot may include an opening or aperture. The slot of this invention always includes a bottom wall and side walls ing.

Prior use of straight angularly ofi'set plug bars set in grooves have entailed the making of a groove of uniconical plug body A is shown I and is therefore not an openform depth obliquely of the curved surface of the plug body sometimes by guiding and supporting the cutting tool on the surface of the curved portion of the plug. Thus as the cutter proceeded longitudinally along the curved surface of the plug body it removed the same depth of material not only from the end portions of the groove but also from the central portion.

To fit and seat a straight bar in such a groove, it was necessary to form a concave lower face on the bottom of the bar because the angular offset of the groove cause it to follow an arcuate path conforming to the curve of the conical plug surface.

While such a bar might be inserted radially into the groove and then anchored as well as possible by welding, or some similar expedient, if the, groove was undercut and the bar provided with an anchoring flange or rib to provide a firm anchor against centrifugal force, the bar could not be either inserted radially or slid endwise into the groove. It will be apparent that twisted helical bars also cannot be slid endwise into twisted helical grooves but can only be inserted radially and anchored as well as possible even if the groove has parallel walls rather than one wall undercut. The upper face of the straight bar also had to be similarly convexed in order to follow the curvature of the cone and to enable the finished plug to fit within a similar frustro conical shell of a Jordan engine.

As shown in Figs. 1-4, the straight, angularly offset grooves such as 25 of this invention are preferably formed by a machine 15 having a suitable plug carriage 16 slideable in a straight line past rotary cutters 17 and 18. The plug body A is rotatably mounted in bearings 27 and 28 of carriage 16 with the curved-surface portion to be grooved on a horizontal plane at the level of the cutters. The central longitudinal axis X of plug body A, however, is shifted or angularly offset in a horizontal plane through any desired angle such as 12 relative to the straight of rotation of cutter 17 is horizontal while that of cutter 18 is inclined from the horizontal to undercut a side wall of the groove 25 formed by cutter 17 The first straight line passage of carriage 16 under cutters 17 and 18, with the angularly offset plug body A contained therein, will cause cutters 1'7 and 13 to form an undercut groove from the longitudinal axis of body A. The groove 25 is of non-uniform depth, the side walls thereof being higher in the central portion and lower at the opposite end portions. Without bodily moving the plug body, but by merely rotating it on its axis identical grooves may be formed at equally spaced distances entirely around the plug body A as shown in Fig. 4. All of the groovesv such as 25 converge toward each other from the large end 20 toward the small end 22 of plug body A and all grooves are angularly offset an identical amount from the axis X of the plug body. As indicated in Fig. 5, ccr

tain grooves may be of less than full length to accommodate bars such as 19 of less than full length, to form plugs of various well known types.

As shown in Fig. 6, the grooves such as 25 are of taper or wedge shape with a cut under portion 29 for holding a bar or knife in place against the effects of centrifugal force. ingly formed with a longitudinal rib or flange portion 32 engageable under portion 29, the bars preferably having tapered side walls 33 and 34 for retaining separators 35 therebetween, all in a well known manner. All such bars and knives are of generally rectangular cross section although provided with various locking or wedging shapes at the base thereof for retaining the same in the groove or slot of the plug and this invention is obviously usable with bars and grooves having cross sectional shapes other than the one shown in the drawings as an illustration.

In Fig. 8 an enlarged diagrammatic view of a groove and bar of this invention indicates that the bottom wall 25 which is similarly offset The bars or knives 31 are correspond.

line path of carriage 16. The axis is fiat and straight and that the bottom face 38.0f each bar 31 is also fiat and straight. Bottom face 38 thus rests fiatwise against and is supported by the bottom wall 37, preferably throughout its entire length. The straight side walls 39 and 40 of each groove 25 are of gradually increasingheight fromthe ends 20 and 22 of the plug body A toward the intermediate or central portion 21 of the plug body A. The central section 41 of the side Walls 39 or 40 thus is of greater depth or height than the opposite end sections 42 or 43 and may be used to provide an increased area of support to the central section 44 of a bar 31 thereby more firmly holding the same against lateral movement.

After formation of a plurality of spaced apart longitudinally extending grooves 25, each identically angularly offset from the longitudinal centre line of plug body A, a corresponding number of elongated straight bars 31 are each inserted endwise in a groove whereby the upper portions thereof project outwardly from the surface 23; If desired, at this time, separators may be also inserted endwise between the bars 31. Both the bottom faces 38 and the top faces 45 of bars 31 are parallel to each other and straight as indicated in Figs. 5, 6 and 8. The bars 31 are fixed in place against endwise movement in the grooves in any convenient manner such as by spot welding, the use of end rings or plates or other well known expedients.

The side walls of the ordinary separator of wood are tapered to fit between the tapered side walls such as 33 or 34 of a pair of adjacent bars such as 31 and when such separators are slid endwise into position from each opposite end in a plug constructed as thus far described, an additional wedging effect is secured along the bottom face of the separator, due to the upward curve encountered. However, instead of removing part of the forward lower face of each separator to conform to the curved surface of the plugbody A between offset bars and instead of squeezing the bottom face thereof by the above men tioned wedging'action, it is preferred that the metal surface of the plug body A be cut away to accommodate ordinary separators without distortion thereof.

Immediately after the forming of the grooves 25 in the plug body A, the next step is therefore the cutting away of'a portion of the surface of the plug body between each adjacent pair of grooves to flatten the surface. A suitable cutter 54 is substituted for cutters 17 and 18 in the machine 15 and the carriage 16 again passed thereunder in a straight line to reduce the height of the walls 39 and 40 along the central portion 41 of each groove entirely around the circumference of plug body A. The separators are then inserted axially.

The next step in the process of manufacture then comprises the removing of identical portions of the top faces 45. of bars 31 to form an arcuate surface curved to conform to the curved surface 23 of plug body A. Where the offset angle of the bars is considerable, it may be desirable to cut down the opposite end portions in a lathe of any well known type but in most cases, grinding is sufficient. The plug body A with its angularly offset grooves 25 and bars 31 is inserted endwisc into a. special Jordan type engine 48 which may have an inner shell 49 lined with abrasive elements 50 or may have an ordinary inner shell and contain abrasive liquid. The abrasive elements 50 orthe ordinary shell, define a frustro conical inside surface exactly of the diameters desired for the outside or top surfaces 45 of the bars 31. By gradually moving the plug body A, by its shaft 34, further into the shell 50 the top faces 45 of bars 31 are ground down into arcuate shape shown in Fig. 10. The resulting bars 31 each therefore are of generally rectangular cross section, have straight side walls 33 and 34, flat straight bottom faces 38 and longitudinally curved arcuate top faces 46 conforming to the longitudinal curve of the frustro conical plug groove when angularly offset therein.

37 of each groove 25 The Jordan 48 is of a well known type and may have a manually operated thrust screw hand wheel 51 for advancing a plug therein while the shaft 24 is revolved in bearings 52 and 53. It will be apparent that instead of pro-forming an arcuate curved top face in each bar prior which arcuate faces may be out The increased supthe bars, achieved cal Jordan plug body; a plurality of identical straight grooves spaced apart around the curved surface of said plug body and converging toward each other from the large end to the small a plurality of straight, of uniform, generally non spiraled, preformed plug bars rectangular cross section, each bar curved. surface of said frustro conical plug body.

3. In a Jordan plug the combination of a substantially frustro conical Jordan plug body; a plurality of straight plug bar grooves extending longitudinally of the longitudinal, exterior surface of said body and angularly olfset from the longitudinal centre line of the plug body, each groove have a flat straight bottom wall and straight side' walls at least one of which is undercut, and a plurality of straight plug bars each having a flat straight arcuate upper face, longitudinally curved to conform to the substantially frustro conical shape of said body.

combination as specified in claim 3 plus a plua fiat straight lower flat straight plane surface of a frustro conical surfaces and a pair of tapered side faces wedged between the tapered side faces of a pair of adjacent bars.

5. The method of making a Jordan engine plug which comprises the steps of cutting a plurality of spaced apart straight undercut grooves, longitudinally of the curved plug body at identical angles of offset from the longitudinal centre line of said body and to a greater depth below the surface of said body at straight cutting path While the groove centre than at sliding straight plug bars, and top faces endwise into said grooves with the bottom faces thereof fiatwise against and then'removing identical portions of the straight fiat top faces of said bars until said top faces are longitudinally curved to conform to the conical shape of said body.

the groove ends; then axially 6. A method as specified in claim 5 wherein said sively advancing and retracting said plug body along said cutting path, after each such rotation to form additional angularly ofiset grooves in said surface.

7. A method as specified in claim 5 wherein the step I bars endwise into the under-' of axially sliding the plug cut grooves is followed by the step of axially sliding separators endwise between the bars prior to the step of removing portions of the top faces of the bars.

8. A method as specified in claim 5 wherein said removing step includes the steps of first cutting down the major portion of the material of the top face to be removed, and' then revolvmg said plug body and bars within a frustro conical shell of a Jordan engine containing a liquid abrasive comprises the steps of straight, undercut grooves, longitudinally of the curved surface of a frustro conical plug body at identical angles of offset from the longitudinal centre line of said body and to a greater depth below the surface of said body at the plug body centre than at the plug body ends to secure a straight bottom wall in said grooves, then cutting a straight flat surface on said plug body between each adjacent pair of grooves, thereby reducing the height of the grooves at the References Cited in the file of this patent UNITED STATES PATENTS 1,633,308 Bolton June 21, 1927 1,674,231 Thomas June 19, 1928 2,604,824 Draper June 29, 1952 FOREIGN PATENTS 33,939 Germany .c................. Dec. 23, 1885 having straight flat bottom the bottom of said grooves, 

